Bosch 715ES Quick Start Manual

Service Bulletin G3-23
Models: 715ES, C800ES, C920ES, C920ESC, 2400ES, 2700ES
Cleaning and replacing ignition group

Introduction

The ignition group consists of two ignition electrodes and one

flame sensing rod. These components may need to be cleaned
or the entire group replaced if the heater has frequent EC or EA
error codes or fails to produce a spark.

Tools needed:

Phillips head screwdriver

8mm wrench or small adjustable wrench

Fine steel wool for cleaning


Preparation

1. Unplug water heater and turn off gas to heater using installer
supplied manual shut off valve.
2. Loosen two Phillips head screws located at bottom rear of cover.
(Fig. 1, step 1, pos. 1).
3. Lift front cover upward and remove. (Fig. 1, step 1, pos. 2 & 3)
4. Remove combustion cover by unclipping two upper and two
lower clips securing cover. (Fig. 1, step 2)
Step 1 Step 1
3
3

Removing the ignition group

1. Locate ignition group. (Fig. 2, pos. 1).
2. Disconnect two large yellow ignition wires from ignition group.
(Fig. 2, pos. 2)
3. Disconnect small black flame sensor wire from ignition group.
(Fig. 2, pos. 3).
Figure 1
Step 2 Step 2
Figure 2